Power sanding device

ABSTRACT

A power sanding device for sanding irregular surfaces such as those of automobile bodies, comprising a rigid shaft rotatably journaled at one end in a radial handle, an abrasive cylinder comprising a pair of solid spools on said shaft and a resilient block between them, means for urging the spools toward each other to expand the resilient block and thereby releasably lock an abrasive sleeve on the spools for rotation with the shaft, and a flexible shaft secured to the end of the rigid shaft remote from the handle for driving connection to a portable electric drill whereby to permit the user to hold the abrasive cylinder generally parallel to his frontal plane and manipulate the sander with his arms and hands in natural, unstrained positions.

Q United States Patent [151 3,656,920 Helms [451 Apr. 1, 1972 [54] POWER SANDING DEVICE 3,468,073 9/1969 Del Vecchio ..s1/170.1 Inventor: Hosea W Helms, 7336 Lohmeyer Avenue 2,098,449 11/1937 Churchill ..51/170 PT Maplewood, 63143 FOREIGN PATENTS 0R APPLICATIONS 1 1 Filedi g- 5, 1969 277,203 9/1927 Great Britain ..51/170.l 1 Great Britain 1 Primary Examiner-William R. Armstrong [52] US. Cl. ..51/170 PT Atlgrney-Bedell and Burgess [51] Int. Cl ..B24b 23/00 [58] Field of Search ..5 H170 R, 170 PT [57] ABSTRACT A power sanding device for sanding irregular surfaces such as [56'] keferelnces cued those of automobile bodies, comprising a rigid shaft rotatably UNITED STATES N S journaled at one end in a radial handle, an abrasive cylinder comprising a pair of 501161 spools on sa|d shaft and a resilient 492,768 2/1893 Geisenhoner ..5 1/ 170.1 block between them, means f urging the Spools toward each L 1,490 12/191 1 Rasnlesen H1701 other to expand the resilient block and thereby releasably lock 5 3 12/1924 Hfarrls "51/1701 an abrasive sleeve on the spools for rotation with the shaft, 1,751,174 3/1930 R1chards.. ...51/17 and a flexible shaft secured to the end of the rigid shaft remote 2,489,102 1 H1949 Moore ...51/l7O- from the handle for driving connection to a portable electric 1554,76? 5/195l W "51/1701 drill whereby to permit the user to hold the abrasive cylinder 7 5 2/1956 Fleld "51/375 generally parallel to his frontal plane and manipulate the 2,954,652 10/1960 MacFaTland "51/1701 sander with his arms and hands in natural, unstrained posi- 3,l44,738 8/1964 Block ..51/375 0m 3,287,863 11/1966 Field ..51/375 3,381,418 5/1968 Eisbrenner ..5 H1701 13 Claims, 4 Drawing Figures POWER SANDING DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to abrading devices and consists particularly in a portable power sanding device for use on irregular surfaces.

2. The Prior Art I Prior patents show power sanders consisting of a cylinder mounting an abrasive sleeve and rotatably'mounted on a rigid shaft, one end of which is axially extended for mounting in the chuck of a portable electric drill and the other end of which is provided with'a handle extending axially from the shaft.

SUMMARY OF THE INVENTION The invention provides a cylindrical power sander which can easily be handled and manipulated with the operators hands and arms in-natural unstrained positions, by means of a radial handle rotatably mounted on one end of the drive shaft on which is mounted an abrasive cylinder and a flexible shaft capable of transmitting torque through an angle to the sander at the other end of the drive shaft for connection to a portable power drill, whereby the axis of the drill can be at a substantial angle to that of the sander shaft. This permits the operator to keep the common axes of the knuckles of each hand generally perpendicular to the axis of the abrasive cylinder during operation of the device and the drill holding arm parallel to the axis of the drill, which is a more natural position than that required by the prior art constructions in which the knuckle axis of one hand would have to be parallel to the shaft, and the other arm would be perpendicular to the axis of the power drill. For ease in removing and replacing abrasive sleeves, and securing them to the cylinder, the latter consists of two rigid spools with a resilient block between them, mounted on the shaft, and adjustable means for forcing the rigid spools toward each other to compress the resilient block axially and expand it radially to grip the inner surface of the abrasive sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a power sander embodying my invention, showing its operation.

FIG. 2 is a longitudinal sectional view along a diametral plane of the abrasive cylinder.

FIG. 3 is an end 'elevational view showing the left hand end of the device.

FIG. 4 is a fragmentary longitudinal sectional view along a diametral plane of the abrasive cylinder showing a modified drive connection.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The sanding device comprises a'shaft l threaded at its ends as at 3 and 5, and an abrasive cylinder assembly, the core of which comprises a pair of rigid cylindrical spools 7 and 9, preferably ofwood or similar material, both centrally axially apertured as at 11 and slidably mounted on shaft 1 in axially spaced relation with each other; between them is mounted a resilient cylindrical block 13 of elastomeric material, centrally axially apertured as at 15 for mounting on shaft 1. A sleeve 17 of abrasive material is mounted on the outer cylindrical surfaces of spools 7 and 9 and resilient block 13, and nuts 19, threadably mounted on threaded end portions 3 and of shaft 1 are tightened, acting as adjustable abutments through washers 21 against the adjacent ends of spools 7 and 9, to compress resilient block 13 axially and thereby expand it radially against the inner surface of abrasive sleeve 17 and against the surface of shaft 1, to secure sleeve 17 on spools 7 and 9 and to secure the latter against rotation with respect to shaft 1.

To permit powered rotation of shaft 1 and cylinder assembly 7, 9, l3 15,'shaft 1 is formed at its ends with reduced diameter extensions 23 and 25. A radial bar-like handle 27 is apertured at one end as at29 to mount anti-friction bearings 31 by which the handle is rotatably journaled on shaft extension 23. The reduction in diameter of extension 23 defines an annular shoulder 32 which fixes the position of handle 27 axially of the shaft. The extremity of extension 23 is threaded as at 33 to mount nut 35, by which handle 27 is secured to the shaft. Handle 27 is formed along one edge with a plurality of indentations 30 to accommodate the fingers of the operator as he grasps the handle.

For drivably connecting shaft 1 to a driving means, at the end of shaft 1 remote from handle 27, shaft extension 25 is threaded as at 37 and a coil spring 39 is threaded thereon to form a flexible shaft. The reduction in diameter of shaft extension 25 defines an annular shoulder 40, which acts as a stop for spring 39. A short adapter, comprising an end section 41, threaded as at 43, on which the end of spring 39 remote from shaft extension 25 is threaded, and an enlarged collar portion 45 abutting the end of spring 39, has a reduced diameter terminal portion 47 for insertion and securement in chuck 49'of portable power drill 51.

With this construction, the drill may be held by the operator in the normalposition, i.e., generally aligned axially with his forearm, even though the abrasive cylinder assembly is held generally parallel to the frontal plane of the operator.

Operation of the sanding device is as follows: For replacing a worn abrasive sleeve, adapter terminal portion 47 is removed from drill chuck 49, either of nuts 19 on shaft 1 is loosened, thus releasing axial compression of resilient block 13 to permit its radial contraction and release of abrasive sleeve 17, which is then slid axially off the aligned spools 7 and 9 and past spring 39 and adapter 41, 45, 47. A fresh sleeve is slid over the spools and resilient block, and nut 19 is tightened, compressing resilient block 13 axially between spools 7 and 9 and expanding it axially, to lock the several parts of the cylinder assembly, including the abrasive sleeve, to each other and to shaft 1. Adapter terminal portion 47 may then be inserted into power drill chuck 49 and locked therein, and the sander is ready for use. In use, the operator (if righthanded) grasps handle 27 with his left hand, with his fingers nested in indentations 30, and with the fingers of his right hand grasps handle portion 53 of drill 51 in the normal manner, with the drill axis generally parallel to his forearm. The flexible shaft permits the operator to hold the drill thus normally while maintaining the axis of shaft 1 and abrasive cylinder assembly parallel to the surface of the work with which abrasive sleeve 17 is abrasively engaged, and at the same time the operators frontal plane can be maintained parallel to the work and the abrasive cylinder assembly for optimum visibility and control.

In the modified form of the invention, illustrated in FIG. 4, a fixed angle drive device comprising a housing 55, an output shaft 57 journaled therein and internally threaded as at 59 is thereby threadably secured to driving shaft extension 25 in place of spring 39. Output shaft 57 mounts a bevel gear 61 within housing 55, and an input shaft 63 is journaled in housing 55 at a right angle to output shaft 57 and mounts, within housing 55, a bevel gear 65, meshing with gear 61. The outer end portion 67 of shaft 63 is arranged for insertion and securement in the chuck of drill 51. Preferably the right angle drive is constructed with step-up gear speed ratio, e.g., in the order of 1:2, to provide a substantially higher angular velocity on the cylinder than that normally provided by conventional electric power drills.

The exclusive use of all modifications as come within the spirit of the invention is contemplated.

Iclaim:

l. A power sanding device comprising an abrasive cylinder, rigid shaft means projecting from the ends thereof, a radial arm journaled on said rigid shaft means adjacent one end of said cylinder and forming a handle thereon, means secured to said rigid shaft means adjacent the other end of said cylinder for transmitting torque through an angle to said rigid shaft means, portable power means having a drive shaft and a support handle and means on the end of said torque transmitting means remote from said rigid shaft means connecting the same to said drive shaft.

2. A power sanding device according to claim 1 wherein said torque transmitting means is a flexible shaft.

3. A power sanding device according to claim 1 wherein said flexible shaft comprises a coil spring.

4. A power sanding device according to claim 1 wherein said rigid shaft means comprises a single shaft and said abrasive cylinder is centrally apertured and axially slidable on said shaft.

5. A power sanding device according to claim 4 wherein said abrasive cylinder includes a cylindrical core and a removable and replaceable abrasive sleeve mounted thereon.

6. A power sanding device according to claim 5 wherein said cylindrical core comprises a pair of rigid spools spaced apart axially and a resilient cylindrical block is interposed between said spools, said shaft mounting means for urging said spools toward each other to compress said block axially and thereby expand it radially into gripping engagement with said sleeve, said spools nonyieldingly supporting a major portion of said sleeve including the end portions thereof.

7. A power sanding device according to claim 6 wherein said means for urging said spools toward each other comprises a pair of abutments on said shaft adjacent the ends of said cylinder, at least one of said abutments being movable to selected fixed positions axially of said shaft.

8. A power sanding device according to claim 7 wherein the end of said shaft mounting. said adjustable abutment is threaded and said adjustable abutment comprises a nut threadably mounted thereon.

9. A power sanding device according to claim 3 wherein said rigid shaft means projecting from said other end of said cylinder is formed with a threaded extension, said coil spring being threadably secured thereto.

10. A power sanding device according to claim 9 wherein said rigid shaft is formed with a shoulder axially inwardly of said threaded extension and abutting the end of said spring to form a stop therefor and thereby assure that rotation of said spring in one direction is transmitted to said rigid shaft.

11. A power sanding device according to claim 10 wherein said portable power means comprises a portable power drill and said connecting means comprises an adapter having one end formed similar to that of said rigid shaft projecting from said other end of said cylinder and its other end formed for insertion and securement in the chuck of said portable power drill.

12. A power sanding device according to claim 1 wherein said torque transmitting means includes an output shaft connected to said drive shaft, and an input shaft extending in a direction transverse of said output shaft and connected to said drive shaft.

13. A power sanding device according to claim 12 including a pair of meshed bevel gears mounted respectively on said input and output shafts. 

1. A power sanding device comprising an abrasive cylinder, rigid shaft means projecting from the ends thereof, a radial arm journaled on said rigid shaft means adjacent one end of said cylinder and forming a handle thereon, means secured to said rigid shaft means adjacent the other end of said cylinder for transmitting torque through an angle to said rigid shaft means, portable power means having a drive shaft and a support handle and means on the end of said torque transmitting means remote from said rigid shaft means connecting the same to said drive shaft.
 2. A power sanding device according to claim 1 wherein said torque transmitting means is a flexible shaft.
 3. A power sanding device according to claim 1 wherein said flexible shaft comprises a coil spring.
 4. A power sanding device according to claim 1 wherein said rigid shaft means comprises a single shaft and said abrasive cylinder is centrally apertured and axially slidable on said shaft.
 5. A power sanding device according to claim 4 wherein said abrasive cylinder includes a cylindrical core and a removable and replaceable abrasive sleeve mounted thereon.
 6. A power sanding device according to claim 5 wherein said cylindrical core comprises a pair of rigid spools spaced apart axially and a resilient cylindrical block is interposed between said spools, said shaft mounting means for urging said spools toward each other to compress said block axially and thereby expand it radially into gripping engagement with said sleeve, said spools nonyieldingly supporting a major portion of said sleeve including the end portions thereof.
 7. A power sanding device according to claim 6 wherein said means for urging said spools toward each other comprises a pair of abutments on said shaft adjacent the ends of said cylinder, at least one of said abutments being movable to selected fixed positions axially of said shaft.
 8. A power sanding device according to claim 7 wherein the end of said shaft mounting said adjustable abutment is threaded and said adjustable abutment comprises a nut threadably mounted thereon.
 9. A power sanding device according to claim 3 wherein said rigid shaft means projecting from said other end of said cylinder is formed with a threaded extension, said coil spring being threadably secured thereto.
 10. A power sanding device according to claim 9 wherein said rigid shaft is formed with a shoulder axially inwardly of said threaded extension and abutting the end of said spring to form a stop therefor and thereby assure that rotation of said spring in one direction is transmitted to said rigid shaft.
 11. A power sanding device according to claim 10 wherein said portable power means comprises a portable power drill and said connecting means comprises an adapter having one end formed similar to that of said rigid shaft projecting from said other end of said cylinder and its other end formed for insertion And securement in the chuck of said portable power drill.
 12. A power sanding device according to claim 1 wherein said torque transmitting means includes an output shaft connected to said drive shaft, and an input shaft extending in a direction transverse of said output shaft and connected to said drive shaft.
 13. A power sanding device according to claim 12 including a pair of meshed bevel gears mounted respectively on said input and output shafts. 